The present invention relates to an improved track bit, and more particularly, to an improved flat beaded track bit adapted for use in railroad work.
Track bits are specialized twist drills that have long been utilized for drilling holes for bolts in railroad rails in connection with heavy duty, portable track repair work in the field. For at least the past 50 years, the basic design or configuration of track bits in common usage has remained unchanged.
Aside from the fact that the prior track bits have performed reasonably satisfactorily, there are other factors which have apparently restrained or hindered innovation in the track bit art. From their first development, the design of the prior track bits, and more specifically the design of the shank portions of the track bits, have been dictated by the requirements of the holder or driver utilized with the drilling machines long used by the railroads in connection with such track repair work. Because the railroads have a relatively large capital investment in these drilling machines, any newly developed track bit must, as a practical matter, be capable of being gripped or held by these drilling machines.
Moreover, the railroads have long had conservative management and have, traditionally, been reluctant to accept innovations in tooling, particularly in those instances where existing tooling performs relatively satisfactorily. In addition, the drilling machines and track bits are utilized by largely unskilled and unsophisticated workers. Thus, any new track bit, to be acceptable by the railroads and by the railroad workers, must be generally similar, in configuration and mode of operation, to the existing track bits as well as offering significant commercial advantages.
It is a primary object of my present invention to provide an improved, novel track bit which affords twice the effective life, as compared to the track bits previously long used by the railroads, whose design is completely compatible with the drilling machines now in common usage by the railroads, and whose mode of operation is substantially unchanged from that of prior track bits. Moreover, my novel track bit can be manufactured by machine tools for substantially the same cost as the prior track bits, and thus can be sold to the railroad for substantially the same price as the other track bits.
Another object of my present invention is to provide an improved flat beaded track bit which comprises an elongated, generally rectangular member having a first end, a second end, and a middle section disposed midway the first and second ends. The member has first and second substantially flat, parallel side surfaces that extend between the first and second ends and has upper and lower, curved surfaces that extend between the first and second side surfaces and between the first and second ends. First, second, third and fourth longitudinal edges join these four surfaces.
Longitudinal beads are centrally formed on the first and second side surfaces so that the beads are parallel with the central longitudinal axis of the member. These beads, together with the flat, first and second side surfaces, constitute the shank portion of my improved track bit. This shank portion is adapted to be gripped or held by the conventional drilling machines in common usage today by the railroads so that the machines may rotate the member about its central longitudinal axis.
First and second drill bodies are formed on the first and second ends, respectively, of the member. The first drill body is the identical, mirror image of the second drill body. The lands of the drill bodies are formed on the upper and lower surfaces, with the margins of each drill body being disposed along diametrically opposed longitudinal edges. The margins extend from the ends of the member to adjacent to the middle section of the member. The diameter of each of the drill bodies, adjacent to the middle section of the member, is slightly less than the corresponding diameter of each of the drill bodies adjacent to the ends of the member.
Other objects and advantages of the improved, novel flat beaded track bit of my present invention will be apparent to those skilled in the track bit art from the following description of the preferred embodiment of my present invention, taken in conjunction with the accompanying drawings.